Structure of organic aerogels. 1. Morphology and scaling

• Published in: Macromolecules Vol. 26; no. 20; pp. 5487 - 5493
• Main Authors: Pekala, R. W, Schaefer, D. W
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 01-09-1993
• Subjects: 360602 - Other Materials- Structure & Phase Studies; AGING; CATALYSTS; CHEMICAL REACTIONS; DECOMPOSITION; MATERIALS SCIENCE; MICROSTRUCTURE; MORPHOLOGY; ORGANIC COMPOUNDS; ORGANIC POLYMERS; POLYMERIZATION; POLYMERS; PYROLYSIS; SCATTERING; SMALL ANGLE SCATTERING; THERMOCHEMICAL PROCESSES
• ISSN: 0024-9297; 1520-5835
• DOI: 10.1021/ma00072a029

Small-angle X-ray scattering is used to determine the structure of nanoporous organic aerogels made by the base-catalyzed polymerization of resorcinol and formaldehyde. This study probes the effect of several variables on the morphology of the supercritically dried aerogels including catalyst concentration, monomer concentration, acid aging, and pyrolysis. In addition, the development of structure during polymerization and aging of the precursor aquagels is reported. The data are consistent with a smooth-surfaced morphology with no indication of fractal clusters or rough surfaces in the length-scale regime from 10 to 600 [angstrom]. These results, taken together, indicate that microphase separation is the dominant process underlying the morphology of these unique materials.